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Louisiana lost nearly 5,000 km2 of its coastal land area due to relative sea level rise (including local, regional, and global factors driving relative sea level change) since 1932, mirroring both the hazards associated with sea level rise and the time horizons of sea level rise impacts expected this century. This represents an opportunity to examine the relationship between long-term population changes and shoreline change. Based on detailed land change data for the period 1932–2010 and a small area population estimation technique for the period 1940–2010, we examine intra-parish population changes in relation to shoreline changes for the one million plus residents living in the ten coastal parishes of Louisiana. We find that since 1940, only two of the ten coastal parishes exhibited landward population movement, which we define as movement perpendicular to the shoreline, exceeding 1 km. Three parishes exhibited seaward population movement in excess of 1 km. Overall, we find very little net intra-parish landward population movement for the region. Our findings suggest that coastal Louisiana's historical population has not moved in concert with observed shoreline encroachment. We also find a potential tipping point related to population migration when a neighborhood loses at least 50% of its land area. Our findings suggest that this lack of landward population movement could be attributable to either localized adaptation strategies or migrations to other landward areas. [ABSTRACT FROM AUTHOR]

In coming decades, sea level rise associated with climate change will make some communities uninhabitable. Managed retreat, or planned relocation, is a proactive response prior to catastrophic necessity. Managed retreat has disruptive health, sociocultural, and economic impacts on communities that relocate. Health impacts include mental health, social capital, food security, water supply, sanitation, infectious diseases, injury, and health care access. We searched peer-reviewed and gray literature for reports on small island or coastal communities at various stages of relocation primarily due to sea level rise. We reviewed these reports to identify public health impacts and barriers to relocation. We identified eight relevant small communities in the USA (Alaska, Louisiana, and Washington), Panama, Fiji, Papua New Guinea, Solomon Islands, and Vanuatu. Affected populations range from 60 to 2700 persons and are predominantly indigenous people who rely on subsistence fishing and agriculture. Few reports directly addressed public health issues. While some relocations were successful, barriers to relocation in other communities include place attachment, potential loss of livelihoods, and lack of funding, suitable land, community consensus, and governance procedures. Further research is needed on the health impacts of managed retreat and how to facilitate population resilience. Studies could include surveillance of health indicators before and after communities relocate due to sea level rise, drought, or other environmental hazards. Lessons learned may inform relocation of both small and large communities affected by climate change. [ABSTRACT FROM AUTHOR]

Differentiating the impacts of climate change between 1.5°C and 2°C requires a regional and sector-specific perspective. Whereas for some regions and sectors the difference in climate variables might be indistinguishable from natural variability, other areas especially in the tropics and subtropics will experience significant shifts. In addition to region-specific changes in climatic conditions, vulnerability and exposure also differ substantially across the world. Even small differences in climate hazards can translate into sizeable impact differences for particularly vulnerable regions or sectors. Here, we review scientific evidence of regional differences in climate hazards at 1.5°C and 2°C and provide an assessment of selected hotspots of climate change, including small islands as well as rural, urban, and coastal areas in sub-Saharan Africa and South Asia, that are particularly affected by the additional 0.5°C global mean temperature increase. We interlink these with a review of the vulnerability and exposure literature related to these hotspots to provide an integrated perspective on the differences in climate impacts between 1.5°C and 2°C. [ABSTRACT FROM AUTHOR]

The article comments on sea level rise. Topics discussed include the projected variation in global mean sea level (GMSL) increase, the use of tide gauge and satellite altimetry in measuring sea levels, and the concept of local sea level variations. Information on the contribution of melting land-ice in Antarctica and Greenland to sea level rise is also given.

This study models shoreline retreat due to sea level rise by using geographic data and applies the model to future projections of decreases in beach area for 806 beaches in Japan. The model uses a foreshore slope (angle) based on data from a digital elevation model, and influence of the present simplified method for estimation of the shoreline retreat is examined through comparisons with previous studies at typical locations. The proposed method gives a distance of shoreline retreat due to sea level rise similar to that predicted using the Bruun rule for minimal retreat less than 30 m, but the difference becomes substantial for more extensive decreases. The decrease in beach area is projected for different sea level rises based on four Representative Concentration Pathway (RCP) scenarios from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. The decrease in beach area becomes more severe for the RCP8.5 scenario, and the proposed method predicts that a third of current sandy beaches in Japan will disappear. The extent of the decrease depends not only on the sea-level-rise scenario but also on the SLR projection model. [ABSTRACT FROM AUTHOR]

Unique location in the land-sea interface makes mangrove ecosystems most vulnerable to the impacts of predicted sea level rise due to increasing anthropogenic CO 2 emissions. Among others, carbon sink function of these tropical ecosystems that contribute to reduce rising atmospheric CO 2 and temperature, could potentially be affected most. Present study was undertaken to explore the extent of impact of the predicted sea level rise for the region on total organic carbon (TOC) pools of the mangrove ecosystems in Negombo estuary located on the west coast of Sri Lanka. Extents of the coastal inundations under minimum (0.09 m) and maximum (0.88 m) sea level rise scenarios of IPCC for 2100 and an intermediate level of 0.48 m were determined with GIS tools. Estimated total capacity of organic carbon retention by these mangrove areas was 499.45 Mg C ha − 1 of which 84% (418.98 Mg C ha − 1 ) sequestered in the mangrove soil and 16% (80.56 Mg C ha − 1 ) in the vegetation. Total extent of land area potentially affected by inundation under lowest sea level rise scenario was 218.9 ha, while it was 476.2 ha under intermediate rise and 696.0 ha with the predicted maximum sea level rise. Estimated rate of loss of carbon sink function due to inundation by the sea level rise of 0.09 m is 6.30 Mg C ha − 1 y − 1 while the intermediate sea level rise indicated a loss of 9.92 Mg C ha − 1 y − 1 and under maximum sea level rise scenario, this loss further increases up to 11.32 Mg C ha − 1 y − 1 . Adaptation of mangrove plants to withstand inundation and landward migration along with escalated photosynthetic rates, augmented by changing rainfall patterns and availability of nutrients may contribute to reduce the rate of loss of carbon sink function of these mangrove ecosystems. Predictions over change in carbon sequestration function of mangroves in Negombo estuary reveals that it is not only affected by oceanographic and hydrological alterations associated with sea level rise but also by anthropogenic processes, therefore the impacts are site specific in terms of distribution and magnitude. [ABSTRACT FROM AUTHOR]

Recent eustatic sea level rise (SLR) is one of the most striking manifestations of recent climate change as it directly impacts coastal activities and ecosystems. Although global SLR is well-known, local values differ due to vertical land motion, and changes in atmospheric pressure, ocean currents and temperatures. Although a reliable estimation of local SLR trends is needed to assess coastal zone vulnerabilities and plan adaptation strategies, instrumental records are usually short or sparse, especially in developing countries. Here we show that 210 Pb-dated sedimentary records from mangrove saltmarshes can provide useful decadal records of local SLR trends. We quantified sediment accretion rates in sediment cores from remote mangrove saltmarshes of the Yucatan Peninsula. Best SLR records were observed for cores collected near mean sea level (MSL). During most of the XX century the SLR rate ranged from 1-2 mm yr -1 , increased to a maximum of 4.5 ± 0.6 mm yr -1 and the acceleration was 0.13 mm yr -2 . Assuming either a constant SLR rate or acceleration, by the end of this century MSL level will be 39 cm or 91 cm above the present value. Both coastal infrastructures and ecosystems will be negatively affected by SLR and society will need to adapt relatively fast to the new conditions. [ABSTRACT FROM AUTHOR]

Cities are increasingly recognised as places in which climate change risks coalesce and from which climate change adaptation efforts are most likely to be mobilised. In an effort to reduce damages from storm surges and sea-level rise, the City of Cape Town municipal government set out to establish a coastal set-back line. This paper describes the process and highlights the potential for unanticipated conflict and resistance when notions of ‘best practice’ fail to consider local institutional interests and pre-existing legislation. This insight is important as coastal municipalities in South Africa look to implement set-back lines in compliance with the Integrated Coastal Management Act (Act 24 of 2008). McKenna et al. [McKenna, J., Cooper, A., & O'Hagan, A.M., Managing by principle: A critical analysis of the european principles of integrated coastal zone management (ICZM).Marine Policy, 32, 941–955. doi:10.1016/j.marpol.2008.02.005] elucidate the potential for conflicts and contradictions when applying the principles of Integrated Coastal Zone Management in Europe. Developing and a applying a set-back line for Cape Town's coastline was anticipated to be difficult given that the city remains socio-economically unequal and spatially segregated and that the coastline provides multiple different communities with amenities, resources and opportunities at the same time. What was not anticipated was the encountered resistance from within public sector directorates operating under the same policies. The paper suggests that differences in mentalities, technologies and resources (following Wood, J., and Shearing, C., (2007)Imagining security.Devon: Willan Publishing) make for subjective policy interpretations and applications by local officials. Recognising and managing these differences is critical if notions of ‘best practice’ prescribed at higher governance levels are to prove useful to climate change adaptation measures at the local scale. [ABSTRACT FROM PUBLISHER]

Kriebel, D.L. and Geiman, J.D., 2014. A coastal flood stage to define existing and future sea-level hazards. This paper explores the possible definition of a generic coastal flood stage (FS), an elevation at which significant flooding of local infrastructure is initiated, for regional or nationwide use in flood hazard analysis. By using monthly National Oceanic and Atmospheric Administration tidal gauge data from several coastal locations, a coastal FS based on the statistics of extreme high water events is proposed. This statistical FS is then compared to moderate and major FSs established by the National Weather Service with good agreement. Once adopted, the FS serves as a less ambiguous reference elevation or threshold to which the flooding potential of future storm events and sea-level rise can be compared and allows for consistent comparison between different sites. [ABSTRACT FROM AUTHOR]

The coastline of Indonesia, which borders almost 17,500 islands and the sea and extends for more than 80,000 km, is vulnerable to sea level rise. This paper aims to investigate the impact of sea level rise on coastal ecology in Indonesia focusing on coastal area of Jakarta, Pekalongan, Semarang and Demak in the northern part of Java Island. Geo-spatial data, i.e. satellite images and maps were used to monitor the environmental changes and primary data were obtained through field survey and observation on the specified area. In Jakarta, sea level rise has been predicted to bring great damages to infrastructure in coastal area. Multiple impacts of sea level rise towards mangrove, agriculture, and aquaculture ecosystem occurs in Pekalongan. Semarang coastal area also suffers from the widening spread of health problems as the coastal inundation increases. At the same time, Demak experiences major losses on mangrove and aquaculture ecosystem due to sea level rise. [ABSTRACT FROM AUTHOR]

Thirty years of monitoring surveys and shoreline erosion studies (1980-2010) along the South Carolina coast show that artificial beach nourishment and the natural process of inlet shoal bypassing have advanced the shoreline along most of the developed beaches and barrier islands. Of the ~98 mi (~161 km) of developed beaches (including public parks), fully 80% were much healthier in 2010 than in 1980, as evidenced by burial of seawalls, wider berms, and higher dunes. About 15% of the developed beaches are in approximately the same condition as in 1980; the remaining ~5% are considered in worse condition. The balance of South Carolina beaches (~89 mi, ~146 km) are principally wilderness areas with limited public access. The dominant condition of wilderness beaches is high erosion; limited new sand inputs, particularly via inlet bypassing; and accelerated recession as many of these sand-starved beaches wash over salt-marsh deposits. High erosion results from a combination of sand losses to the lagoon, winnowing of muddy marsh deposits outcropping across the receding beach, and longshore transport losses to the adjacent inlet. An estimated 75% of the undeveloped beaches in 2010 were well landward of their 1980 positions. Between 1980 and 2010, -39.4 million yd³ (~30.1 million m³) of beach nourishment from external sources was added to developed and park beaches (~62.6 mi, ~102.6 km). This is equivalent to an addition of ~168 ft (~51 m) of beach width in the nourished areas. Natural shoal bypassing events appear to have added a similar magnitude of new sand along accreting beaches. Bypassing events at some beaches involved -2~5 million yd³ (1.5-3.8 million m³). Ebb dominance at many South Carolina inlets is shown to play an important role in preserving the littoral sand budget, maintaining large sand reservoirs for bypassing and helping maintain the developed beaches in the state. Low rates of erosion in other areas, such as the Grand Strand, combined with large-scale nourishment have advanced those beaches well beyond historic conditions. [ABSTRACT FROM AUTHOR]

As sea level rise accelerates and land development intensifies along coastlines, tidal wetlands will become increasingly threatened by coastal squeeze. Barriers that protect inland areas from rising sea level prevent or reduce tidal flows, and impermeable surfaces prevent wetland migration to the adjacent uplands. As vegetation succumbs to submergence by rising sea levels on the seaward edge of a wetland, those wetlands prevented from inland migration will decrease in area, if not disappear completely. Tools to identify locations where coastal squeeze is likely to occur are needed for coastal management. We have developed a ''Coastal Squeeze Index'' that can be used to assess the potential of coastal squeeze along the borders of a single wetland and to rank the threats faced by multiple wetlands. The index is based on surrounding topography and impervious surfaces derived from light detection and ranging and advanced spaceborne thermal emission and reflection radiometry imagery, respectively, and uses a fuzzy logic approach. We assume that coastal squeeze varies continuously over the coastal landscape and tested several fuzzy logic functions before assigning a continuous weight, from 0 to 1, corresponding to the influence of slope and impervious surfaces on coastal squeeze. We then combined the ranked variables to produce a map of coastal squeeze as a continuous index. Using this index, we compare the present and future threat of coastal squeeze to marshes in Wells and Portland, Maine, in the United States and Kouchibouguac National Park in New Brunswick, Canada. [ABSTRACT FROM AUTHOR]

Coastal flood risk in California is concentrated around urbanized embayments that are protected by infrastructure, such as levees, pumps, and flood walls, which pose a challenge to accurate flood prediction. A capability to predict coastal urban flooding at the parcel-scale (individual home or street) from high ocean levels (extreme high tides) is shown here by coupling a regional ocean forecasting system to an embayment-scale hydrodynamic model that incorporates detailed information about flood defenses. A unique flooding data set affords the rare opportunity to validate model predictions and allows us to identify model data that are essential for accurate forecasting. In particular, results show that flood defense height data are critical, and here, that information is supplied by a Real Time Kinematic Global Positioning System (RTK-GPS) survey, which yields ca. 1-cm, vertical root mean-squared error accuracy. Bathymetry surveys and aerial Light Detection and Ranging (LIDAR) data characterizing the embayment also prove essential. Moreover, hydrodynamic modeling of flood inundation is shown to significantly improve on planar surface models, which overestimate inundation, particularly when manipulated to account for run-up in a simplistic way. This is attributed to the transient nature of overtopping flows and motivates the need for dynamic, spatially-distributed overtopping models that are tailored to the urban environment. [ABSTRACT FROM AUTHOR]

Climate change-induced rises in sea level threaten to drastically reduce the areal extent of important salt marsh habitats for large numbers of waterfowl and waders. Furthermore, recent changes in management practice have rendered existent salt marshes unfavourable to many birds, as lack of grazing has induced an increase in high-sward communities on former good-quality marshes., Based on a high-resolution digital elevation model and two scenarios for projected rise in near-future sea levels, we employ an Arc Map allocation model to foresee the areal loss in salt marsh associated with these changes. In addition, we quantify the areal extent of inadequate salt marsh management in four EU Special Protection Areas for Birds, and demonstrate concurrent population dynamics in four species relying on managed habitats. We conclude by investigating potential compensation for climate change-induced salt marsh losses by means of more efficient management., Our models indicate that by the end of this century 15·3-43·6% of existent salt marshes will be flooded due to rising sea levels, and that inadequate managed salt marsh presently makes up around 51·1% of total marshes. Thus, re-establishing extensive areas of well-managed marshes might counterbalance the loss expected from rising sea levels during the next century., In addition to positive effects on plant diversity, this will benefit energetically challenged herbivorous waterfowl such as light-bellied brent geese Branta bernicla hrota L. and increase potential recovery of wader populations with unfavourable conservation status such as black-tailed godwit Limosa limosa L., dunlin Calidris alpina L. and ruff Philomachus pugnax L., Synthesis and applications. Implementing environmentally friendly management schemes based on extensive grazing (around 1 cow per hectare) is an important initiative to counteract the accelerating climate change-induced habitat loss in near-coastal areas across the globe, and to secure priority salt marsh habitats that support internationally important populations of breeding, wintering and staging waterfowl. However, this may only be a temporary solution that will have to be supplemented by increased reintegration with the sea and managed retreat of seawalls or near-coastal agricultural areas to effectively safeguard the future salt marsh biome. [ABSTRACT FROM AUTHOR]

Changing climates are affecting biodiversity and natural systems, causing extinctions, range shifts, and phenological shifts. Efforts to forecast the spatial distribution and magnitude of these effects, however, have focused largely on direct effects of changing climates on species' distributional potential; recent work has considered secondary effects of warming climates via rising sea levels. Here, we present a first integration of the two dimensions of climate change effects on biodiversity, examining joint effects of marine intrusion and climate change on the distributional potential of seventy-six species of Mexican birds. The two phenomena are not related to one another—that is, a species seriously affected by one is not necessarily seriously affected by the other; however, the areas affected within species' distributions by the two phenomena tend to be complementary, compounding the negative effects. These results have implications for planning biodiversity conservation globally. [ABSTRACT FROM AUTHOR]